George r



(No Model.)

G. R. CLARKE.

GALIPERS.

No. 585,184. Patented June 29, 1897.v

INVENTOR:

WITNESSES:

` .A torney.

' UNITED STATES ArnN'r retenu.

GEORGE R. CLARKE, OF MONTELL, TEXAS, ASSIGNOR OF ONE-HALF TO LEOPOLD IIEYMA'NN, OF NEIV YORK, N. Y.

CALIPERS.

SPECIFICATION forming part of Letters Patent No. 585,184, dated June 29, 1897.

Application filed June 29, 1896.

To @ZZ whom, t may conceive:

Be it known that I, GEORGE R. CLARKE, a citizenof the United States, residing at Montell, Uvalde county, Texas, have invented certain new and useful Improvements inOalipers, of which the following is a specification.

Myinvention relates to calipers for either inside or outside measurements; and the object is to provide for a quick and simple adjustment of the calipers to nearly the proper dimensions and then an equally quick and simple adjustment to the exact measurement within one ive-thousandt-h of an inch, or even less. Indeed, one of the features of the calipers is the ability to adjust micrometrically and at the same time to effect this adjustment by a considerable movement marked by widely-spaced graduations which may be easily read.

Another object of the invention is to attain a simple and inexpensive construction, so that the instrument may be within the reach of any good mechanic.

In the drawings which illustrate an embodiment of the invention, Figure l is a longitudinal section of the calipers. Fig. 2 is an elevation as seen vfrom below in Fig. l. Fig. S is a transverse section on the line 3 3 in Fig. 2.

The stock l is a metal tube which I prefer to make of accuratelydrawn steel tubing. On the end of this tube is fixed, preferably by shrinking, the fixed jaw 2 ofthe calipers. The tube l has in it two oppositely-arranged longitudinal slots 3 it is mounted to slide the movable jaw 2Xof the calipers. The jaws 2 and 2X will be by preference of steel, formed in the ing such parts. The sleeve of the jaw 2X will snugly on the tube l. In the tube l is fitted snugly a rod 4, which will be, by preference, of steel and accurately drawn. This .rod is provided with two sitely-arranged longitudinal grooves 5, which and in the slots 8 in the tube fit gibs 6 and 6X, the wider ends of which engage recesses in the sleeve of the movable jaw 2X. This jaw may be moved along the tube l and rod 4, carr 7ing with it the gibs, and it may be fixed firmly in place on the rod 4 by means Oppobetween the inner way usually employed in makt Serial No. 597,342. (No model.)

of a set-screw 7 in the boss of the jaw2X, the tip of said screw bearing on the gib 6.

Along one margin of the slot 3 in the tube is a series of graduations S (to any standard, as inches, for example) for outside calipering faces of the jaws, and along the other margin of theslot is asimilar series ot' graduations f), adapted for inside calipering between the outer faces of said jaws. It is not very important just Where these graduations are placed about the tube, and there may be two sets adapted for different standards, as inches, centimeters, duc.

In order to get miorometrical adjustments of the movable jaw 2X, I employ the means which will now be described.

In the outer end of the tube l (at the right in Fig. l) is formed a female screw l0, and on the reduced end of the rod I at that end of the tube is formed a male screw ll. These screws differ in pitch, but the direction of the pitch may be the same-that is, they may both be right-hand or both left-hand screws.

Fitted snugly on the end of the tube l is a sleeve-cap l2, which has fixed in it, concentrically, an inner nut-sleeve 13, having a male screw to fit the female screw l0 and a female screw to fit the male screw 1l.

f We suppose that the screws l0 and l1 are respectively vtwenty pitch and twenty-five pitch and the sleeve-cap 12 be turned once around, (by means of t-he milled bead 12X thereon,) the rod et, carrying the jaw 2X, will be moved relatively to the tube l a distance equal to one one-hundredth of an inch. Now if the beveled end 14 of the sleeve-cap l2 be provided with,say,ten equally-spaced graduation-marks a rotative movement of the sleevecap to the extent of one such division will move the jaw 2X to the extent of one onethousandth of an inch. Subdivisions of the spaces indicated by the graduations at lat would indicate a movement of the jaw one two-thousandths of an inch. Ot' course other proportions may be employed between the pitches of the screws 10 and 1l.

The mode of using the calipers will be readily understood. Suppose itis desired to turn down a piston, plunger, uc., to a diameter a very little in excess of two inches. The workman relaxes the set-screw Tand sets the jaw.

2 'to two inches on the scale 8, clamps it fast to the rod 4 by the screw 7, and then turns the sleeve-nut 12 in the proper direction and to the proper extent to move the jaw 2X, say, to the extent of two one-thousandths of an inch outwardly or from the xed jaw 2.' The user will readily understand how to set and employ the calipers for other purposes.

It will be readily understood that the object in using the differential screw is to allow the use of relatively coarse graduations on the nut-sleeve at 14, which can be easily seen by the eye, thus enabling the user to set his calipers .micrometrically with ease and without `the aid of-a magnifyingglass. Having thus described my invention, I

1; In calipers, the combination with av tubular, slotted stock, of the fixed jaw secured thereto, the movable, jaw having a sleeve mounted on said stock, the set-screw in said sleeve, the rod in vsaid stock, said rod having longitudinal, oppositely-arranged grooves coincident with the slots in the stock, the gibs engaging the said grooves and situated in the sleeve on the movable jaw, one of said gibs being under said set-screw, and means substantially as described for moving said rod, micrometrically, in the tubular stock.

` 2. In calipers, the combination with a tubular stoek having oppositely-arranged slots 3, 3, and a fixed jaw secured thereon, of a movable jaw having a sleeve embracing said Stock, the rod in said stock, said rod having' longitudinal grooves coincident wit-h the slots in the stock, a gib engaging the sleeve A of the movable jaw and a slot in the stock and bearing on said rod, means for clamping said gib onto said rod, and means for moving said rod micrometrically in the stock, said means comprising the sleeve-cap 12, having the nutsleeve 13, adapted to screw onto the said rod and into the stock, substantially as set forth.

In witness whereof have hereunto signed my name in the presence ot' two subscribing witnesses.

GEORGE n. CLARKE.

Witnesses:

HENRY CoNNE'rT, 'lii'rnn A. Ross. 

